HTTP request failed Length required - php

Question

I humbly come before the people for some much needed assistance with this..
I am using (or trying to use) the skyscanner API - http://partners.api.skyscanner.net/apiservices/pricing/v1.0 as documented here. But I am coming up against this error:
HTTP request failed! HTTP/1.1 411 Length Required
PHP attempt 1
function getSkyScanner() {
$url = 'http://partners.api.skyscanner.net/apiservices/pricing/v1.0?apiKey=MY-API-KEY';
$headers = array( 'Content-Type' => 'application/x-www-form-urlencoded',
'Accept' => 'application/xml');
$contextData = array (
'method' => 'POST',
'header' => $headers);
$context = stream_context_create (array ( 'http' => $contextData ));
$result = file_get_contents($url, false, $context);
if ($result === FALSE) { echo 'error'; }
var_dump($result);
}
My server doesn't support cURL so I'm in need of a solution without it. I'm using localhost with WAMP but I have also tried a live version which comes up with the same error and seemingly same problem. I have tried almost every combination of variables in order to correct the error with a discouraging amount of success (none). This is one such variation including the form contents that I am attempting to send.
PHP attempt 2
function getSkyScanner() {
$url = 'http://partners.api.skyscanner.net/apiservices/pricing/v1.0?apiKey=MY-API-KEY';
$params = array( 'country' => 'GB',
'currency' => 'GBP',
'locale' => 'en-GB',
'originplace' => 'LHR',
'destinationplace' => 'EDI',
'outbounddate' => '2016-10-10',
'adults' => '1'
);
$query = http_build_query($params);
$headers = array( 'Content-Type' => 'application/x-www-form-urlencoded',
'Accept' => 'application/xml');
$contextData = array (
'method' => 'POST',
'header' => $headers,
'content' => $query );
$context = stream_context_create (array ( 'http' => $contextData ));
$result = file_get_contents($url, false, $context);
if ($result === FALSE) { echo 'error'; }
var_dump($result);
}
This throws out:
Content-type not specified
Followed by:
HTTP/1.1 400 Bad Request
If you can help I would appreciate some insight right about now.
Many thanks!

Answer 1

You create headers in a wrong way - instead of an array, headers should be passed as a string.
$headers = "Content-Type: application/x-www-form-urlencoded\r\n" .
"Accept: application/xml\r\n";
You can use below snippet to create the correct request:
function prepare_headers($headers) {
return
implode('', array_map(function($key, $value) {
return "$key: $value\r\n";
}, array_keys($headers), array_values($headers))
);
}
function http_post($url, $data, $ignore_errors = false) {
$data_query = http_build_query($data);
$data_len = strlen($data_query);
$headers = array(
'Content-Type' => 'application/x-www-form-urlencoded',
'Accept' => 'application/xml',
'Content-Length' => $data_len
);
$response =
file_get_contents($url, false, stream_context_create(
array('http' => array(
'method' => 'POST',
'header' => prepare_headers($headers),
'content' => $data_query,
'ignore_errors' => $ignore_errors
)
)
));
return (false === $response) ? false :
array(
'headers' => $http_response_header,
'body' => $response
);
}
Example usage of http_post method:
$result = http_post('http://business.skyscanner.net/apiservices/pricing/v1.0', array(
'apiKey' => 'YOUR_API_KEY',
'country' => 'UK',
'currency' => 'GBP',
'locale' => 'en-GB',
'locationSchema' => 'iata',
'originplace' => 'EDI',
'destinationplace' => 'LHR',
'outbounddate' => '2016-10-10',
'adults' => '1'
), false);
Parameter $ignore_errors in http_post method is reponsible for fetching the content even on failure status codes (400, 500, etc.). If you receive Bad request, set ignore_errors = true -> you'll receive full response from server.